JP2018026157A - Generating haptic effects while minimizing cascading - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide realistic feedback to alert a user to specific events, or to create greater sensory immersion within a simulated or virtual environment.SOLUTION: A processor 12 outputs control signals to an actuator drive circuit 16 that is used to supply actuator 18 with electrical impulse current and voltage required to cause desired haptic effects. A touch surface 11 recognizes a touch, and may also recognize a position and magnitude of a touch on the surface. Data corresponding to a touch is sent to the processor 12 or another processor within a system 10. The processor 12 interprets the touch and generates a haptic effect signal in response.SELECTED DRAWING: Figure 1

Description

  One embodiment relates generally to haptic effects, and more particularly to generating haptic effects using actuators.

  Electronic device manufacturers are striving to provide a rich interface for users. Conventional devices use visual and auditory cues to provide feedback to the user. In some interface devices, kinesthetic feedback (eg, active and resistive force feedback) and / or haptic feedback (eg, vibration, texture and heat) are also provided to the user, and more generally “haptic feedback” Or “haptic effect”. Haptic feedback can provide cues that facilitate and simplify the user interface. In particular, vibration effects or vibrotactile haptic effects are electronic devices for informing users of specific events or providing realistic feedback to create deeper perceptual immersion in a simulated or virtual environment Useful for providing user queues.

  Haptic feedback is also increasingly incorporated into portable electronic devices such as mobile phones, smartphones, portable gaming devices and various other portable electronic devices. For example, some portable gaming applications can vibrate in a manner similar to control devices (eg, joysticks, etc.) used in large gaming systems configured to provide haptic feedback. Furthermore, devices such as smartphones allow “buttons” on the touch screen to feel like mechanical when they are selected by the user.

  Many devices use some type of actuator / motor or haptic output device to generate the vibration effect. Existing actuators used for this purpose include electromagnetic actuators, such as eccentric rotating mass (“ERM”) actuators, whose eccentric mass is moved by a motor and rotates about a rotational axis. However, due to inertia, the ERM's eccentric mass takes time to reach and lower the desired rotational speed. This “spin up” and “spin down” time causes a delay in the generation of the vibration type haptic effect and reduces the “feel” of the haptic effect. In particular, multiple haptic effects generated within a short period of time, such as responses to multiple “keypad” presses, are continuous “noise” due to slow and less expensive ERM delays. Are "cascaded" or accumulated.

  One embodiment is a system that generates a haptic effect using an actuator. The system accepts a haptic effect definition that defines a haptic effect. The system preprocesses the haptic effect definition by determining whether the actuator is capable of playing the haptic effect. While playing the haptic effect, the system post-processes the haptic effect by adjusting the force value based on an estimation or measurement of the actuator state.

FIG. 1 is a block diagram of a haptically enabled system according to an embodiment of the present invention. FIG. 2 is a flow chart of the functionality of the system of FIG. 1 when generating a minimal or cascadeless haptic effect according to one embodiment of the present invention. FIG. 3 is a flow chart of the functions of the system of FIG. 1 when preprocessing a haptic effect definition according to an embodiment of the present invention when three haptic regions are used. FIG. 4 illustrates an example effect illustrating the functionality of FIG. 3 according to one embodiment. FIG. 5 is a flowchart of functions of the system of FIG. 1 when post-processing a haptic effect definition according to one embodiment of the present invention.

  One embodiment is a system and drive circuit for an ERM actuator that adjusts, pre-processes, and post-processes haptic effect definitions to occupy actuator characteristics and minimize cascading of multiple haptic effects. . The preprocessing can scale the magnitude or other parameters of the haptic effect. Post processing can generate a new magnitude based on the actuator characteristics, the current actuator state and the desired magnitude.

  FIG. 1 is a block diagram of a hapticly-enabled system 10 according to an embodiment of the present invention. The system 10 may include a touch-sensitive surface 11 or other type of user interface implemented in the housing 15 and may include mechanical keys / buttons 13. Inside the system 10 is a haptic feedback system that generates vibrations 30, 31 in the system 10. In one embodiment, the vibration is generated on the touch surface 11. In various embodiments, not all of the elements shown in FIG. 1 are required for implementation.

  The haptic feedback system includes a processor or controller 12. A memory 20 and an actuator drive circuit 16 are connected to the processor 12, and the actuator drive circuit 16 is connected to an actuator 18. Actuator 18 may be any type of actuator, including an actuator having a rotating mass, and in one embodiment is an eccentric rotating mass (“ERM”) actuator. In one embodiment, actuator 18 is any type of actuator that has relatively long rise and fall times. The processor 12 may be any type of general purpose processor or may be a processor specifically designed to provide a haptic effect, such as an application specific integrated circuit (“ASIC”). it can. The processor 12 may be the same processor that operates the entire system 10 or may be a different processor. The processor 12 can determine which haptic effects are played and the order in which the haptic effects are played based on the high level parameters. Typically, the high level parameters that define a particular haptic effect include magnitude, frequency and duration. Low level parameters such as streaming motor commands are also used to determine specific haptic effects. A haptic effect is considered "dynamic" if it contains several variations of these parameters when the haptic effect is generated or is a variation of these parameters based on user interaction Also good.

  The processor 12 outputs a control signal to the actuator drive circuit 16, which provides the actuator 18 with the necessary electrical impulse current and voltage (ie, “motor signal”) to produce the desired haptic effect. Including electronic components and circuits used to The system 10 may include one or more actuators 18, and each actuator may include a separate drive circuit 16, all connected to a common processor 12. The memory device 20 can be any type of storage device or computer readable medium such as random access memory (RAM) or read only memory (ROM). The memory 20 stores instructions executed by the processor 12. Of the instructions, the memory 20 includes a haptic effect module 22 that provides a haptic effect when executed by the processor 12, while minimizing the cascade, as disclosed in more detail below. A drive signal is generated for use. Memory 20 may be located within processor 12 or any combination of internal and external memory.

  The touch surface 11 recognizes a touch and may also recognize the position and magnitude of the touch on the surface. Data corresponding to the touch is transmitted to the processor 12 or another processor in the system 10, which reads the touch and generates a haptic effect signal accordingly. The touch surface 11 may detect a touch using any sensing technique including capacitance detection, resistance detection, surface acoustic wave detection, pressure detection, optical detection, and the like. The touch surface 11 may detect multi-touch contact and may be able to distinguish between multi-touches that occur at the same time. The touch surface 11 may be a touch screen that generates and displays images for a user to interact with keys, dials, etc., or may be a touch pad with minimal or no image.

  System 10 may be a mobile phone, personal digital assistant (“PDA”), smart phone, computer tablet, gaming console, wearable device, or any other including a haptic effects system that includes one or more actuators. This type of device may be used. The system 10 may be a wearable device that includes one or more actuators that generate haptic effects (eg, bracelets, armbands, gloves, jackets, vests, glasses, shoes, belts, etc.). The user interface may be a touch-sensitive surface or any other type of user interface such as a mouse, touchpad, mini joystick, scroll wheel, trackball, game pad or game controller. . In embodiments having more than one actuator, each actuator may have a different rotational performance to produce a wide range of haptic effects on the device.

  As mentioned above, there are some typical latencies when playing vibration haptic effects with actuators with long rise and fall times, such as ERM or other types of low speed motors. Thus, when playing a series of fast haptic effects, such as a response to a continuous press of a virtual key on a touch screen keyboard, a continuous buzz is generated, which is referred to as “cascading”. be called. Cascading occurs because after the first effect is played, the motor does not stop when subsequent effects are received. As a result, the motor rotates continuously, and when the haptic effects are played within a short period of each other, the user cannot feel the individual haptic effects. Known solutions to cascading problems use relatively expensive ERMs with fast rise and fall times, and use relatively expensive drive circuits that support bi-directional drive signals including braking signals. Or some means to prevent the haptic effect from being played fast.

  Embodiments include pre-processing and post-processing of haptic effect signals to accommodate slow rise and fall times of the actuator and to minimize cascading. Prior to pre-processing and post-processing, the embodiment “tunes” the actuator to characterize the rise and fall times of the actuator and occupy variations in those times. Some embodiments may implement only pre-processing or post-processing to minimize or eliminate cascading. Other embodiments may implement both pre-processing and post-processing to minimize or eliminate cascading.

  Specifically, the low speed actuator has non-linear rise and fall times. In order to be able to model such an actuator, the embodiment measures the total rise time obtained from the actuator to rise to 90% of the rated acceleration from a standstill. This rise time in one embodiment is 10%, 20%. . . Divided into 10 sections at 90%, the corresponding acceleration at each point is described. These nine values + total rise time are added to the tuning parameters. In general, any number of points / sections can be selected, and more points can be taken along the rising curve and modeled more accurately. Each actuator on the device has its own set of 99 tuning parameters in one embodiment. Changing these parameters results in different haptic effects. Examples of tuning parameters are: (1) a gain value for scaling the magnitude, (2) a linearization value to help obtain a linear response from the non-linear actuator, (3) a MagSweeper effect kick and brake parameter , (4) Periodic effect parameters, (5) Update rate (eg, 5 ms) and (6) Information parameters such as actuator type, build number, etc.

  Similar to the rising curve, 10 values are obtained for the falling curve in one embodiment, but any number of values can be used. The fall time is considered to be the time required for the actuator to reach a perceivable acceleration (˜0.04 g in one embodiment) from the rated acceleration. Where braking is supported by the actuator, other braking mechanisms such as negative overdrive voltage or shunting are applied. Otherwise, no voltage is applied. By applying this tuning model, the embodiment has a more accurate picture of the effects that the motor can play and the state of the motor at a given time.

  FIG. 2 is a flowchart of the functionality of system 10 when generating a haptic effect that minimizes or does not have cascades according to an embodiment of the present invention. In one embodiment, the functions of the flowcharts of FIGS. 2, 3 and 5 are implemented by software (eg, haptic effects module 22) stored in memory or other computer readable or tangible media and executed by a processor. . In other embodiments, the functionality may be performed by hardware (eg, through use of an application specific integrated circuit (ASIC), programmable gate array (PGA), field programmable gate array (FPGA), etc.)). Or any combination of hardware and software.

  At 202, the haptic effect is accepted in the form of a parameterized vibration definition that defines the envelope / shape of the haptic effect. The definition includes parameters that define haptic effects including duration, frequency, magnitude, etc. In one embodiment, the definition is based on the “TouchSense® 3000 Haptic Design Kit” by Immersion Corp. In this embodiment, the haptic effect has the three basics of “impulse”, “sustain” and “fade” formed from MagSweep or Periodic basic effects. Defined by a defined shape formed by an envelope containing a part / region or effect magnitude. Other effect types such as Timelines and Interpolated effects constitute basic effects. In other embodiments, the definition is a general one of haptic effects that are relatively maintained through the functionality of FIG.

  At 204, the haptic effect definition is preprocessed. Typically, preprocessing modifies the haptic effect to match the characteristics of the actuator 18 in the system 10 by determining the desired haptic effect and determining the actual effect, and the actuator It becomes possible to be played based on. A “new” effect is either the same as the original effect or a scaled down version. For example, if the haptic effect definition is very strong in a short time, the actuator cannot rotate quickly. Thus, pre-processing changes the haptic effect definition to adjust the actuator, such as magnitude reduction, before the haptic effect is played. In one embodiment, the pre-processing includes “clipping” based on the desired effect to be played and based on the actuator rise and / or fall curves. Clipping occurs at the base effect level and ensures that the actuator can achieve the desired magnitude at the end of the duration of the effect. Thus, if the same effect is played repeatedly, the effects are not merged with each other, preventing cascading. Usually, the pre-processing changes the effect in such a way that the cascading is reduced or not reduced but maintains the effect characteristics with respect to each other as much as possible. Other methods in addition to or instead of magnitude scaling can be used, including effect duration scaling. Further details of the pretreatment are disclosed below.

  At 206, the preprocessed haptic effect is initiated / played by sending a preprocess signal to the drive circuit, which causes the actuator to generate a vibration haptic effect.

  While the haptic effect is being played, it is determined whether a post-processing interval has been reached. The post-processing interval is predetermined and is typically equal to timer / clock tick / cycle (eg, every 5 ms) and has a force value sent to the drive circuit. It happens every time before.

  If 208 is no, at 212, the haptic effect continues to play until its duration ends, and the flow moves to 208.

  If yes at 208, then at 210, the haptic effect definition is post-processed. Typically, post-processing estimates or measures the actuator located on its rising or falling curve at a given point (ie, the current state of the actuator) and adjusts the force / voltage value sent to the actuator drive circuit. Is done. The value of the force indicates how fast the motor is desired to be spun based on the effect definition at a particular time. Post-processing determines the current state of the actuator along with the desired effect force and determines a new force / magnitude. The new force may be similar to the desired force, or may be a force that causes the actuator to achieve the desired force as soon as possible. The force value may be received from an external entity such as a kernel from Immersion Corp's “TouchSense® 3000 Haptic Design Kit”. Post processing adjusts the force value based on an estimate or measurement of the current state of the actuator (ie, how fast it is already rotating). Further details of post-processing are disclosed below.

  At 212, the haptic effect is played after post-processing at 210. The flow moves to 208.

  FIG. 3 is a flow chart of the functions of the system 10 when pre-processing haptic effect definitions according to some embodiments of the present invention when three effect areas are used. Typically, for this embodiment, the maximum magnitude (“newMax”) that the actuator can achieve is determined outside of three regions (ie, impulse, sustain, and fade). All three regions are then scaled using the “newMax / oldMax” ratio. Therefore, the effect shape is maintained. FIG. 4 illustrates exemplary effects illustrating the functionality of FIG. 3 according to one embodiment.

  Specifically, as shown in FIG. 3, at 302, the effect is divided into three magnitude segments / regions: impulse, sustain, and fade. The impulse and fade regions can be flat or ramp up or ramp down. The sustain area is always flat in one embodiment.

  The variable “oldMax” is equal to the maximum magnitude of the three categories. In FIG. 4, the original effect impulse segment 402 is the first segment and ends at 420. The next segment is the sustain segment that ends at 430. Finally, the fade segment ends the effect.

  At 304, it is determined whether the impulse segment is ramped down and intersects the rising curve of the actuator. In FIG. 4, the impulse segment does not ramp down and intersects the rising curve 406 at 414.

  If yes at 304, then at 306, the variable “newMax” is equal to the impulse crossing level and the variable “Susachieved” is equal to 1. In FIG. 4, the impulse crossing level is the first clipping 409.

  If no at 304 (ie, the impulse is ramped down), at 308 newMax is equal to the sustain crossing level of the rising curve. The variable Susachieved is equal to 1 if the sustain crossing level is greater than the sustain level. At 310, it is determined whether the fade segment is ramped down. If 310 is yes, then 312 determines whether Susachieved is equal to 1. If the variable Susachieved = 1, the flow moves to 316.

  If no at 310 or 312, at 314, the level of intersection between the fade segment and the rising curve is determined. If the rising curve does not intersect the fade section, fadeIntersectLevel is set to the maximum that the rising curve can be realized in the fade duration. If the intersection level is greater than newMax, newMax is set to the intersection level. In FIG. 4, the curve 407 is not intersected, and the maximum value is the second clipping 411, which is larger than the first clipping 409.

  At 316, the scale factor of newMax / oldMax is determined. The original effect is scaled to an effect scaled based on the scale factor by multiplying the magnitude level by the scale factor. In FIG. 4, the scale factor is 0.75, and the original effect 402 is scaled to the scale effect 403.

  As described above, pre-processing scales the overall effect to what an actuator can achieve, while maintaining the effect shape (or maintaining the original effect). The flow determines the maximum magnitude (denoted “oldMax”) outside the initial ramp, sustain and fade magnitude. The flow then finds three magnitudes that can actually be realized based on the actuator rise curve crossing the effect curve (ie, “ImpIntersectLevel”, “SusIntersectLevel”, and “FadeInterceptLevel”). newMax is the maximum of these three effect magnitudes. Finally, the scale factor of newMax / oldMax is determined. All three effect magnitudes in the original effect are multiplied by this scale factor to reach a new magnitude.

  In other embodiments, instead of clipping effect magnitude, the effect duration can be clipped. Furthermore, both effect duration and magnitude can be clipped. For this embodiment, a normal is drawn from the effect to the rising curve, and the magnitude and duration at the intersection of the vertical and the rising curve are used.

  In another embodiment, the area under the effect curve is determined and used to play the effect. This embodiment assumes that for very slow motors, the user cannot know the difference between different effect shapes. In another embodiment, the duration of the effect can be determined, and the determination is made as to how fast the actuator will eventually become after the duration starting from zero, with the effect having a maximum magnitude. In the case of a maximum pulse (maximum magnitude square pulse), the effect magnitude, impulse level, and fade level may be limited to the values. Further, embodiments may have another clipping process for “Timeline” haptic effects. Periodic, Magsweep, and Waveform effects can be replaced with a Timeline to form a complex effect sequence.

  FIG. 5 is a flowchart of functions of the system 10 when post-processing a haptic effect definition according to an embodiment of the present invention. Typically, the post-processing function of FIG. 5 is performed every timer tick / cycle and is typically 5 ms. Each time, the embodiment calculates a new force / voltage to determine and send the desired force to the actuator (ie, partially overdrive or rotate the motor at the desired speed). Brake). Embodiments are based on a haptic effect compared to how fast a motor can rotate by considering an estimate of which motor is currently running relative to where the actuator is on the rising or falling curve. How fast the motor should rotate. The embodiment computes the voltage that rotates the motor as close as possible to the desired speed, and then updates / recalculates the estimated speed, which is desirable if the motor cannot reach the desired speed of the timer tick. Will not be the same as the speed.

  At 502, it is determined whether the desired force / output is equal to the estimated output. If yes at 502, the output is linearized at 504. Output linearization typically adds real-world parameters such as friction to the output decision. For example, friction at the actuator may mean that 15% force is needed to produce 1% force based on the haptic effect. In some embodiments, a table or other mapping is used for linearization.

  If no in 502, then in 506, the variable “Diff” is determined as (desired output) − (estimated output).

  In 508, it is determined whether Diff is greater than zero.

  If yes at 508, the rise time that the actuator can be realized in one timer tick is determined. In one embodiment, a lookup table based on the rise time slope of the actuator is used for the determination. The lookup table is generated based on the tuning function described above before the preprocessing. When the lookup table is generated, it is used for pre-processing and post-processing.

  At 512, it is determined whether Diff is greater than the rising slope.

  If yes at 512, then at 514, Diff is equal to the rising slope and the output is equal to the maximum output of the actuator.

  If 512 is no, the new output is determined using linear interpolation between the two points. Additional details regarding linear interpolation are disclosed below. In other embodiments, any type of interpolation model can be used.

  At 524, Estimate is equal to Diff, and New Force is equal to the output.

  At 526, the output is linearized as 504.

  If Diff does not exceed 0 at 508, then at 518, the falling slope that the actuator can achieve in one timer tick is determined. In one embodiment, a lookup table based on the actuator fall time slope is used for the determination.

  At 520, it is determined whether Diff is below the falling slope.

  If yes at 520, at 522, Diff is equal to the falling slope and the output is equal to zero or negative maximum power based on the braking capability. The flow then moves to 524.

  If no at 520, the flow moves to 516.

  As described above, for post-processing, the actuator rise and fall curves are divided into ten straight line segments based on changes to the tuning process. The increase / phenomenon of the maximum force value in the timer tick is determined based on the slope of these line segments. The slope is used to determine whether the actuator acquires the desired force value on the next timer tick. Otherwise, a kick or brake pulse is applied. If the actuator can obtain the desired force on the next timer tick, the amount by which the force should be increased / decreased is determined so that the actuator is at the desired force value upon expiration of the timer tick. . The estimated force is updated every tick as shown in FIG.

In one embodiment, the post-processing can be implemented with pseudo code whose parameter definitions are as follows:
• Smax-maximum 'strength'representation; e. g. , 63
-'Strength' means "effect designer intent"
Vmax-maximum voltage representation; e. g. , 127
Ttic-update period; e. g. , 5ms
Vrat-rated voltage representation (<= Vmax)
・ Trise-time to go from 0 to Smax when applying Vmax
Tfall-time to go from Smax to 0 when applying-Vmax

The derived parameters are as follows.
Mmax-maximum strength-versus-time slope
-When applying Vmax
-The actuator can't accelerate any faster than this.
− Mmax = Smax / Trise
− Mmax> 0
Mmin-minimum strength-versus-time slope
-When applying-Vmax
-The actuator can't slow down any faster than this.
− Mmin = −Smax / Tfall
− Mmin <0

The input is as follows:
• Sdes-desired strength at time t + Tick
-This is what the effect designer wants to feel.
-Sdes> = 0

The state variables are as follows:
-Estimated strength at time t
-This is what the simulation 'thinks' the user is feeling.
-Sest> = 0

The desired slope is as follows.
Mdes-This is the need to go from Set to Sdes in Tick
-Mdes = (Sdes-Test) / Ttick

The possible slopes are as follows.
・ Clip Mdes to what the actuator can achieve
-Mout = MAX (MIN (Mdes, Mmax), Mmin)

The output voltage is as follows.
If Mout = 0,
− Vout1 = Vrat * Sest / Smax
− In order to maintain Test
If Mout = Mmax,
− Vout2 = Vmax
If Mout = Mmin,
−Vout2 = −Vmax
・ Interpolate linearly
−Vout = Vout1 + (Vout2−Vout1) * Mout / (Mout> = 0? Mmax: Mmin)

Finally, the updated state is as follows.
・ Estimate state at time t + Ttic
-Sest '= Sest + Mout * Ttick

  As disclosed, embodiments generate haptic effects by pre-processing and / or post-processing haptic effect definitions. Preprocessing looks up the actuator characteristics along with the desired effect and determines whether the actual effect is playable by the actuator. The preprocessed effect is either the same as the original effect or scaled down. The pre-processing is changed so that the haptic effect can be realized before the haptic effect is played.

  The post processing looks up the desired force along with the current state of the actuator to retrieve a new force. This new force may be the same as the desired force, or the force at which the actuator obtains the desired force as soon as possible. Pre-processing implemented together in one embodiment or separately in other embodiments (ie, one embodiment only implements pre-processing and other embodiments only implement post-processing) And as a result of post-processing, cascading from a series of quick haptic effects, such as successive keypad presses, is minimized or eliminated.

  This specification specifically illustrates and / or describes several embodiments. However, modifications and variations of the disclosed embodiments are also within the scope of the above teaching and are intended to be included within the scope of the appended claims without departing from the spirit and scope of the present invention.

Claims (27)

A computer readable medium having instructions that, when executed by a processor, cause the processor to generate a haptic effect using an actuator, the generating the haptic effect comprises:
Receiving a haptic effect definition defining the haptic effect;
Pre-processing the haptic effect definition comprising determining whether an actuator can play the haptic effect;
Post-processing the haptic effect definition comprising adjusting a force value based on an estimate or measurement of the state of the actuator during play of the haptic effect.   The computer-readable medium of claim 1, wherein estimating the state of the actuator is based on estimating where the actuator is located on a rise time curve or a fall time curve.   The computer-readable medium of claim 1, wherein the haptic effect definition comprises a parameterized vibration definition that defines an envelope of the haptic effect.   The computer-readable medium of claim 3, wherein the parameterized vibration definition has one or more parameters including at least one of duration, frequency, or magnitude.   The computer-readable medium of claim 1, wherein the actuator includes a characteristic and the determining is based at least on the characteristic.   The computer-readable medium of claim 1, wherein the preprocessing step includes scaling down the haptic effect.   The computer-readable medium of claim 1, wherein the post-processing step is performed each time before the force value is transmitted to a drive circuit for an actuator.   The computer-readable medium of claim 1, wherein the preprocessed haptic effect is played and the post-processing step occurs when the haptic effect is played.   The computer-readable medium of claim 8, wherein the haptic effect is played by transmitting the haptic effect to the actuator. A method for generating a haptic effect using an actuator,
Receiving a haptic effect definition defining the haptic effect;
Pre-processing the haptic effect definition comprising determining whether the actuator can play the haptic effect;
Post-processing the haptic effect definition including adjusting a force value based on an estimation or measurement of the actuator state during play of the haptic effect.   The method of claim 10, wherein estimating the state of the actuator is based on estimating where the actuator is located on a rise time curve or a fall time curve.   The method of claim 10, wherein the haptic effect definition includes a parameterized vibration definition that defines an envelope of the haptic effect.   The method of claim 12, wherein the parameterized vibration definition has one or more parameters including at least one of duration, frequency, or magnitude.   The method of claim 10, wherein the actuator includes a characteristic and the determining is based at least on the characteristic.   The method of claim 10, wherein the preprocessing step includes scaling down the haptic effect.   The method of claim 10, wherein the post-processing step is performed each time before the force value is transmitted to the actuator drive circuit.   The method of claim 10, wherein the preprocessed haptic effect is played and the post-processing step occurs when the haptic effect is played.   The method of claim 17, wherein the haptic effect is played by transmitting the haptic effect to the actuator. A haptically enabled system,
A controller that accepts a haptic effect definition that defines the haptic effect;
A drive circuit connected to the controller;
An actuator connected to the drive circuit;
A preprocessor connected to the drive circuit for preprocessing the haptic effect definition comprising determining whether the actuator can play the haptic effect;
A post-processor connected to the drive circuit for post-processing the haptic effect definition including adjusting a force value based on an estimation or measurement of the actuator state during play of the haptic effect. .   The system of claim 19, wherein estimating the state of the actuator is based on estimating where the actuator is located on a rise time curve or a fall time curve.   The system of claim 19, wherein the haptic effect definition includes a parameterized vibration definition that defines an envelope of the haptic effect.   24. The system of claim 21, wherein the parameterized vibration definition has one or more parameters including at least one of duration, frequency, or magnitude.   The system of claim 19, wherein the actuator includes a characteristic and the determining is based at least on the characteristic.   The system of claim 19, wherein the preprocessing includes scaling down the haptic effect.   The system according to claim 19, wherein the post-processing is executed each time before a force value is transmitted to the driving circuit.   The system of claim 19, wherein the preprocessed haptic effect is played and the post-processing occurs when the haptic effect is played.   27. The system of claim 26, wherein the haptic effect is played by transmitting the haptic effect to the actuator.